Secrets of the London Underground

Tim Dunn and Siddy Holloway explore the shortest branch line on the London Underground network.

Siddy takes Tim on a mystery tour of a secret station deep beneath Hampstead Heath.

Tim and Siddy explore the disused parts of Piccadilly Circus.

Tim and Siddy explore the hidden parts of Euston underground station

Tim and Siddy have a night-time adventure as they go on a late-night exploration.

Tim and Siddy are deep beneath Clapham Common; they're so deep, the Northern line is running above their heads.